A waterless dye composition for apparel and other articles, made from thermoplastic materials, comprises an aliphatic polyester of a higher alkanoic acid and a polyol, of the formula (ACOO).sub.2-6 B, wherein A is alkyl of 8-22 carbon atoms and B is the residue of a polyhydric alcohol, other than glycerol, of 2-6 hydroxyl groups and an organic colorant. The compositions can further comprise an aromatic polyester of the formula C.sub.6 H.sub.z' --(COOR.sub.1).sub.z, wherein z is 3, 4, 5, or 6; z' is 6-z; and R.sub.1 is higher alkyl; and/or a cycloaliphatic diester of the formula ##STR1## wherein R is substituted or unsubstituted straight or branched chain alkyl of 4-20 carbon atoms, polyoxyalkylene of the formula HO(C.sub.x H.sub.y O).sub.n C.sub.x H.sub.y -- or phosphated polyoxyalkylene of the formula (HO).sub.2 P(.dbd.O)O(C.sub.x H.sub.2x O).sub.n C.sub.x H.sub.2x or a salt thereof, wherein (C.sub.x H.sub.2x O).sub.n is (CH.sub.2 CH.sub.2 O).sub.n, (C.sub.3 H.sub.6 O).sub.n or (CH.sub.2 CH.sub.2 O).sub.p (C.sub.3 H.sub.6 O).sub.q, n is 2-22, and the sum of p+q is n.A process for coloring apparel or other articles, fabricated from polyester, polyamide, polyurethane, acrylic, halogenated polyolefin or epoxy plastic, comprises exposing an article to the foregoing compositions, maintained at a temperature between 100.degree. C. and the temperature at which the plastic is degraded, for a time adequate to achieve the desired degree of coloration.The compositions may further be diluted with water and used for textile finishing processes or as dyeing assistants in aqueous baths.